Das Mitschreiben hilft mir, den Lernstoff besser zu verstehen.

Because Mitschreiben is being used as a noun, not as a normal verb here.

• mitschreiben = to take notes / to write along
• das Mitschreiben = note-taking / taking notes

In German, when a verb is turned into a noun this way, it is:

• capitalized
• usually neuter, so it takes das

So das Mitschreiben means the act of taking notes or simply taking notes.

Not quite.

mitschreiben usually means to write along while listening, especially in class or during a lecture — in natural English, often to take notes.

aufschreiben means more generally to write something down.

So:

• mitschreiben = take notes as someone is speaking or teaching
• aufschreiben = write something down, record it in writing

In this sentence, Mitschreiben fits well because it refers to note-taking during learning.

Because helfen takes the dative case, not the accusative.

So:

• jemandem helfen = to help someone

That gives:

• hilft mir = helps me

Not:

• hilft mich ❌

This is something English speakers often just have to memorize: helfen + dative.

That part is an infinitive clause with zu:

• den Lernstoff besser zu verstehen = to understand the material better

In modern German, the comma before this kind of zu-infinitive is often used for clarity. In a sentence like this, it is very common and sounds natural.

So the structure is:

• Das Mitschreiben hilft mir, ...
• ..., den Lernstoff besser zu verstehen.

The comma marks off the extra idea: what note-taking helps me do.

Because German infinitive clauses normally put the verb at the end.

Here the infinitive clause is:

• den Lernstoff besser zu verstehen

Its basic structure is:

• object: den Lernstoff
• adverb: besser
• infinitive verb: zu verstehen

So the verb comes last, which is very normal in German subordinate or infinitive structures.

Because Lernstoff is the direct object of verstehen, and verstehen takes the accusative.

• der Lernstoff = the learning material / subject matter
• accusative masculine: den Lernstoff

So:

• den Lernstoff verstehen = to understand the material

If the noun were feminine or neuter, the article would look different.

Lernstoff means learning material, course material, or the content being studied.

Depending on context, it could refer to:

• class material
• subject matter
• material for an exam
• what you are supposed to learn

It is a useful school and study word.

Yes. besser is the comparative form of gut and here it works adverbially.

So:

• gut verstehen = understand well
• besser verstehen = understand better

In natural English, this might also sound like:

• understand more clearly
• understand more effectively
• understand more easily

But grammatically, it is simply better.

Because after helfen, German often uses a zu-infinitive to say what someone is helped to do.

Pattern:

• jemandem helfen, etwas zu tun

So:

• Das Mitschreiben hilft mir, den Lernstoff besser zu verstehen.

Literally:

• Taking notes helps me to understand the material better.

In English, we often omit to in some similar structures, but in German zu is required here.

Yes, you can.

Both are possible:

• Das Mitschreiben hilft mir ...
• Mitschreiben hilft mir ...

The version with das sounds a bit more like the activity of taking notes as a general thing.
Without the article, it can sound slightly more general or abstract.

In many contexts, both would be understood perfectly.

Because this sentence is not mainly expressing purpose. It is expressing what helps me.

• hilft mir, den Lernstoff besser zu verstehen = helps me understand the material better

If you used um ... zu, that would emphasize purpose:

• Ich schreibe mit, um den Lernstoff besser zu verstehen.
• I take notes in order to understand the material better.

So:

• helfen + zu-infinitive = helps someone do something
• um ... zu = in order to do something

Both are possible in German, but they express slightly different relationships.

The main clause is:

• Das Mitschreiben hilft mir

Then comes the infinitive clause:

• den Lernstoff besser zu verstehen

So the full structure is:

• subject: Das Mitschreiben
• verb: hilft
• indirect object (dative): mir
• infinitive clause: den Lernstoff besser zu verstehen

A rough grammar breakdown is:

[Taking notes] [helps] [me] [to understand the material better].

That is why the sentence feels a little different from English word order, even though the meaning is straightforward.